Data output printer

ABSTRACT

Rotatably driven type wheels carrying type characters on the periphery thereof are supported resiliently about a normal operating axis for movement to a printing position to impact a selected type character against a recording medium. The movement of the type wheel to the printing position is accomplished by engaging a relatively stationary stop member with an abutment on the type wheel to stop the normal rotational movement of the type wheel and enable the associated rotational kinetic energy to pivot the type wheel about the stop member to impact the selected type character against the recording medium at the printing position. To ensure full engagement of the stop member with the abutment on the type wheel and reduce the accompanying stresses, the stop member yieldably engages the abutment prior to stopping the normal rotational movement of the type wheel.

United States Patent 1191 Nure e e y.

Kohlhage June 4, 1974 15 1 DATA OUTPUT PRINTER 3,384,216 5/1968 Thayer 197/53 x [75] Inventor: girl :2? Kohlhage, Nuremberg, Primary Examiner Robert E. Pulfrey y Assistant ExaminerR. T. Rader [73] Assignee: Triumph Werke Nuremberg A.G.,

[ 5 7 ABSTRACT Rotatably driven type wheels carrying type characters on the periphery thereof are supported resiliently about a normal operating axis for movement to a printing position to impact a selected type character against a recording medium. The movement of the type wheel to the printing position is accomplished by engaging a relatively stationary stop member with an abutment on the type wheel to stop the normal rotational movement of the type wheel and enable the associated rotational kinetic energy to pivot the type wheel about the stop member to impact the selected type character against the recording medium at the printing position. To ensure full engagement of the stop member with the abutment on the type wheel and reduce the accompanying stresses, the stop member yieldably engages the abutment prior to stopping the normal rotational movement of the type wheel.

3 Claims, 4 Drawing Figures I DATA OUTPUT PRINTER v This invention relates to a data printing apparatus having a rotatably driven type wheel which is moved to a printing position to impact a type character on the periphery of the wheel against a recording medium, and more particular to a printing apparatus in which the type wheel is moved to the printing position by using the rotational kinetic energy associated with the rotatably driven wheel.

In a data printer, for example one which may be used with an electronic table calculator, it is desirable that the printing operation be accomplished with a minimum of noise and vibration. However, in a data printer using the rotational kinetic energy associated with the rotatably driven wheel to move it to the printing position, the printing operation is usually accompanied by jarring vibrations and noise as the wheel is diverted from a normal rotating position to a printing position.

Furthermore, the portions of the data printer used in.

diverting the rotatably driven type wheel to the printing position undergo abrasive contact resulting in undesirable wear on the parts.

In the past, there have been data printers in which a rotatably driven type wheel was moved to the printing position by using the associated rotational kinetic energy, and attempts have been made to reduce or eliminate the jarring vibrations, noise and abrasive wear which accompanied the printing operation. For example, in German Patent No. CH-l09,322, and US. Pat. No. 1,520,089 the braking mechanism used to divert the rotatably driven type wheel from a normal operating position to a printing position was interconnected to the type wheel by means of slip clutch so as to more I which a rotatably driven type wheel is moved to the printing position by using the associated rotational kinetic energy.

Still other objects, features and advantages of the present invention will be apparent to those skilled in the art from a reading of the following detailed description of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side elevational view of a data printer according to the present invention with a rotatably driven type wheel in a normal operating position,

FIG. 2 shows the rotatably driven type wheel at the printing position with a type character impacting against a platen,

FIG. 3 shows another embodiment of a data printer constructed according to the present invention with a rotatably driven type wheel in a normal operating position, and

FIG. 4 shows the embodiment of FIG. 3 when a printing operation is initiated.

Referring generally to the figures in the drawing, and more particularly to FIG. 1, there is shown a data printer, generally indicated 11, for printing characters or symbols onto a recording medium 13 in response to data signals. The recording medium 13 is located beside a suitable marking material 15, and between a platen 17 which is located at a printing position, generally indicated at 19, and a type wheel 21 which is located at a normal operating position, generally indicated at 23. The type wheel 21 has a plurality of type characters 25 formed on the periphery thereof, and is rotatably driven in the direction indicated by the arrow shown in FIG. 1. When a selected character is to be printed onto the recording medium 13, the type wheel 21 is moved from the normal operating position 23 to the printing position 19 where the selected type charac ter is impacted against the platen 17. After a line of type has been printed, the recording medium 13 may be advanced by a suitable sheet feeding mechanism, not shown, for printing another line of type. In addition, the marking material 15 may be advanced past the printing position 19 in preparation for another printing operation.

As shown, the recording medium 13 is fed upwardly from a suitable supply roll 27 which may be contained in a concave pan 29 formed from a portion of housing 31 of the data printer 11. The marking material 15 may be located on either side of the recording medium 13, and may be in the form of a suitable inked ribbon. The

means foradvancing the recording medium 13 and the means for advancing the marking materiallS are not shown, since they form no part of the present invention and may be conventional. Furthermore, the recording medium 13 and the marking material 15 have been deleted from theother figures of the drawing for clarity in showing the operation of the data printer 11 during a printing operation. Although only a single type wheel 21 is shown in FIG. I, it is to be understood that a plurality of type wheels may be located at the normal operating position and rotatably driven in the direction of the arrow.

In the normal operating position, the type wheel 21 is supported for rotation about a normal operating axis, and maybe rotatably driven by drive means in the form of a drive shaft 33 which is rotatable about its axis. To minimize the space required for the data printer 11, each of the type wheels 21 may be in the form of a ring having an interior opening or bore 35 through which the drive shaft 33 is received. The type wheel 21 may be rotatably driven in concentric relation with the axis of the rotating drive shaft 33 by suitably resilient means in the form of springs 37 connected between the type wheel 21 and the rotatable drive shaft 33. As shown,

the drive shaft 33 has flutes or ribs 33a, 33b, 33c and the springs 37 are each stretched between a suitable projecting eyelet 39a, 39b, 39c formed on the interior surface of the type wheel 21 and an eyelet formed in each of the ribs 33a, 33b, 330 of the drive shaft 33. The type wheel 21 is prevented from relative rotational movement about the drive shaft 33 in the direction of rotation as indicated by the arrow by means of wedgeshaped interior abutments 41 projecting from the interior surface 35 of the type wheel 21 and having forward surfaces 43 engaging the ribs 33a, 33b, 33c of the drive shaft 33.

To print a selected type character on the recording medium 13, the type wheel 21 is moved from the normal operating position 23, as shown in FIG. 1, to the printing position 19, as shown in FIG. 2, to impact the type character 25 against the recording medium 13. To

' accomplish this movement, stop means are provided for momentarily stopping the rotational movement of the type wheel 21. at a location radially spaced from the normal operating axis so as to enable the rotational kinetic energy-associated with the type wheel 21 to pivotally move it to the printing position 19.

As shown, the stop means may include a plurality of stop abutments 45 formed on the periphery of the type wheel 21 and a stop engaging means in the form of a pawl 47 which is movable into engagement with the stop abutment 45. The stop abutments 45 are each formed between a pair of type characters 25 on the periphery of the type wheel 21, and the pawl 47 is supported adjacent the periphery of the type wheel 21 for pivotal movement about a suitable rod or axis 49 located in the housing 31 of the data printer 11. To move the pawl 47 in response to a data signal for printing a selected type character, a solenoid 51 may be provided having a plunger 53 operably connected to the pawl 47 for pivotally moving the pawl 47 about the rod 49 and into engagement with a particular stop abutment 45. To provide for simultaneous printing of several type characters along the line of type, each one of a plurality of rotatably driven type wheels at the normal operating position may be provided with a separate pawl and associated solenoid.

Accordingly, when a particular type character 25 is to be printed onto the recording medium 13 as shown in FIG. 2,,the solenoid 51 is energized in response to a data signal for moving the pawl 47 into engagement with a particular stop abutment 45 associated with the type character 25 selected to be printed. When the pawl engages the selected stop abutment 45, the rotational movement of the type wheel 21 about the normal operating axis is momentarily stopped, and the rotational kinetic energy associated with the type 'wheel moves the wheel pivotally about the end of the pawl 47 to strike the selected type character 25 against the platen 19 to mark the recording medium 13. As shown in FIG. 2, as the type wheel 21 moves to the printing position 19, the drive shaft 33 continues torotatably drive the type wheel 21 with the resilient means 37 enabling the type wheel to move laterally from the normal operating position 23 to the printing position 19.

Upon movement of the type wheel 21 to the printing position l9, the resilient means 37 exerts a return force against the pawl 47 urging the type wheel 21 back to able noise as the type wheel 21 is diverted to the printing position 19. In addition, a sudden and rigid engagement of the pawl 47 with a stop abutment 45 may not result in full engagement with the stop abutment 45 to provide proper printing. Furthermore, the movement of the pawl 47 into engagementwith a stop abutment 45 and the subsequent forcible disengagement results in undersirable abrasive contact and wear.

In accordance'with the present invention, the jolting impact of the pawl 47 with a stop abutment 45 is 'reduced by providing stop engaging means which flexibly divert the type wheel 21 from the normal operating position 23 to the printing position 19. As shown in FIGS. 1 and 2, the stop engaging meansincludes a pawl 47 having a U-shaped bent portion 55 located between the pawl tooth and the pivot rod 49 so as to resiliently yield about the bent portion upon engagement with the stop abutment 45 to flexibly pivot the type wheel 21 to the printing position 19. In addition, when the type wheel 21 is at the printing position 19, the yielding of the pawl 47 about the U-shaped bent portion 55 facilitates the removal of the pawl 47 from engagement with the stop abutment 45-and hence serves to reduce undesirable wear.

Another embodiment of the invention is shown in FIGS; 3 and 4, and the printing mechanism is operable in the same manner as previously described in connection with FIGS. 1 and 2. This embodiment is generally similar to the embodiment shown in FIGS. 1 and 2, and accordingly similar parts have been identified with like reference numerals. In this embodiment, the stop engaging means includes a pawl 47 which is slidably supported about the rod 49 which is received in a guide slot 57 formed in the pawl 47. As shown in FIG. 3, the pawl 47 is normally urged in one direction about the rod 49 by resilient means of a flat leaf spring 59 pressing against one end of the guide slot abuts the rod 49.

The leaf spring 59 may be secured to a portion of the the normal operating position 23. To return the type wheel 21 from the printing position 19, the pawl 47 is forcibly driven from engagement with the stop abutment 45 by suitable means, not shown, and returned to its normal positiomas shown in FIG. 1. Although not shown, the removal of the pawl 47 from engagement with the stop abutment 45 may be accomplished by suitable spring means. When the pawl 47 is removed from engagement with the stop abutment 45, the'type wheel 21 returns to its normal operating position 23 with the forward edges 43 of the interior wedge-shaped stop abutment 41 again engaging the ribs 33a, 33b, 33c of the drive shaft 33' to prevent relative rotational movement in the direction indicated by the arrow shown in FIG. 1.

From the foregoing, it will be apparent that the engagement of a rapidly rotating stop abutment 45 on the driven type wheel 21 with the relatively stationary pawl 47 will 'result in a sharp jolt to the housing 31 of the data printer llalong with the accompanying undesirhousing 31 of the data printer 11 by suitable means, for example screws or bolts.

In operation, the pawl 47 yieldably engages an abutment 45 of the type wheel 21 by sliding about the rod 49 against the urging of the leaf spring59 prior to stopping the normal rotational movement of the type wheel 21, as shown in FIG. 4. Subsequently, when the pawl 47 is driven from engagement with the stop abutment 45, the pawl 47 is slidably returned to the normal operating position, as shown in FIG. 3, by the urging of the flat leaf spring 59.

While only a limited number of embodiments have been illustrated and described, it will be apparent to those skilled in the art that various modifications and improvements may be made without departingfrom the scope and spirit'of the invention. Accordingly, it is to be understood that the invention is not to be limited by the illustrative embodiments, but only by the scope of the appended claims.

What is claimed is':

1. In a printing machine having a type wheel resiliently supported about an axis at a normal operating position for being rotatably-driven, a type character on the periphery of the type wheel for impacting against a recording medium at a printing position spaced apart from the normal operating position, a stop abutment on the type wheel operably associated with the type character and radially spaced from the axis of rotation of the type wheel, and a stop engaging means into engagement with the stop abutment in response to a signal to print the associated type character by enabling rotational kinetic energy associated with the type wheel to pivot the type wheel about the stop engaging means and displace the axis of rotation of the type wheel from the axis at the operating position, the improvement comprising:

said stop engaging means including a stop member having a stop portion for engaging the stop abutment of said type wheel and being pivotally supported about a pivot point fixedly spaced from said axis at the normal operating position for pivotal movement into engagement with the stop abutment, and

said stop engaging means further including resilient means resiliently flexing in response to the force of said type wheel upon engagement of the stop portion with the stop abutment for enabling said stop member to undergo a yielding movement while said type wheel pivots about the stop portion during movement from the normal operating axis to impact the type character against the recording medium at the printing position.

6 2. In a printing machine according to claim 1, said stop member being constructed from a resilient material and said resilient means being in the form of a bend in said stop member between the stop portion and the pivot point fixedly located from the axis at the normal operating position for resiliently deforming upon engagement of the stop portion with said stop abutment prior to stopping the normal rotational movement of said type wheel about the normal operating axis.

3. In a printing machine according to claim 1: said stop member being supported for slidable movement about the pivot point fixedly spaced from the axis at the normal operating position, said resilient means being in the form of biasing means for slidably urging said stop member in one direction about the pivot point, and said stop member being slidably movable in an opposite direction against the urging of said resilient biasing means to yieldably engage said stop abutment on said type wheel prior to stopping the normal rotational movement of said type wheel about the normal operating axis. 

1. In a printing machine having a type wheel resiliently supported about an axis at a normal operating position for being rotatably driven, a type character on the periphery of the type wheel for impacting against a recording medium at a printing position spaced apart from the normal operating position, a stop abutment on the type wheel operably associated with the type character and radially spaced from the axis of rotation of the type wheel, and a stop engaging means into engagement with the stop abutment in response to a signal to print the associated type character by enabling rotational kinetic energy associated with the type wheel to pivot the type wheel about the stop engaging means and displace the axis of rotation of the type wheel from the axis at the operating position, the improvement comprising: said stop engaging means including a stop member having a stop portion for engaging the stop abutment of said type wheel and being pivotally supported about a pivot point fixedly spaced from said axis at the normal operating position for pivotal movement into engagement with the stop abutment, and said stop engaging means further including resilient means resiliently flexing in response to the force of said type wheel upon engagement of the stop portion with the stop abutment for enabling said stop member to undergo a yielding movement while said type wheel pivots about the stop portion during movement from the normal operating axis to impact the type character against the recording medium at the printing position.
 2. In a printing machine according to claim 1, said stop member being constructed from a resilient material and said resilient means being in the form of a bend in said stop member between the stop portion and the pivot point fixedly located from the axis at the normal operating position for resiliently deforming upon engagement of the stop portion with said stop abutment prior to stopping the normal rotational movement of said type wheel about the normal operating axis.
 3. In a printing machine according to claim 1: said stop member being supported for slidable movement about the pivot point fixedly spaced from the axis at the normal operating position, said resilient means being in the form of biasing means for slidably urging said stop member in one direction about the pivot point, and said stop member being slidably movable in an opposite direction against the urging of said resilient biasing means to yieldably engage said stop abutment on said type wheel prior to stopping the normal rotational movement of said type wheel about the normal operating axis. 